The typical hard disk drive includes a head disk assembly (HDA) and a printed circuit board assembly (PCBA) attached to a disk drive base of the HDA. The HDA includes at least one disk, a spindle motor for rotating the disk, and a head stack assembly (HSA). The PCBA includes a disk controller for generating servo control signals. The HSA includes a head for reading and writing data from and to the disk. The HSA is controllably positioned in response to the generated servo control signals from the disk controller to move the head relative to tracks of the disk.
The HSA includes an actuator assembly, at least one head gimbal assembly (HGA), and a flex cable assembly. The actuator assembly typically includes an actuator having an actuator body with one or more actuator arms extending from the actuator body. Each actuator arm supports the HGA that includes a head. An actuator coil is supported by the actuator body. The actuator coil interacts with a magnet to form a voice coil motor. The PCBA controls current passing through the actuator coil that results in a torque being applied to the actuator. The HSA further includes the flex cable assembly in electrical communication with the PCBA. The flex cable assembly supplies current to the coil and carries signals between the head and the PCBA.
A latching mechanism is provided to retain the actuator in a parked position when the heads are not being used to interact with the tracks on the disk. In the parked position, the actuator is positioned with the heads either at an inner diameter (ID) of the disk or at or beyond an outer diameter (OD) of the disk such as upon a ramp. A crash stop coupled to the disk drive base is provided to limit rotation of the actuator in a given direction. The crash stop is configured to contact a portion of the actuator when the actuator is rotated in a given rotational direction. Another crash stop may be provided to limit actuator rotation in an opposite rotational direction. The latching mechanism may additionally function as one of the crash stops.
Disk drives have found an ever increasing utility in small mobile electronic devices. Such devices may include laptop and hand-held computing devices, audio devices, audio/video devices, and personal electronic organizers, for examples.
Due to the portable nature of such small mobile electronic devices, there is an enhanced risk that the device may be subject to mechanical shock events. This may occur in the case where the device is dropped for example. During a mechanical shock event, the disk drive base may experience significant rotational acceleration that can cause a sudden relative rotation of the actuator. Such sudden relative rotation of the actuator may result in damage to the actuator, especially the attached head gimbal assemblies. The adjacent disk(s) may be impacted as well, which may result in loss of data. Various latch designs have attempted to secure the actuator during such mechanical shock events. However, many such designs have proven to be complex, costly or unreliable. In addition, it is desirable to have the ability to readily remove the actuator from the disk drive for purposes of reworking and/or replacing the actuator without having to first remove the latch.
Accordingly, there is need in the art for an improved actuator latch or latch/crash stop configuration that facilitates installation, removal, or replacement of the actuator.